For centuries selective breeding techniques have been employed to generate animal offspring having preferred qualities such as size, productivity and temperament. Male animals having desirable genetic characteristics may naturally sire offspring by multiple females in a single season. In recent times artificial insemination techniques have made possible the generation of thousands of offspring from a single parent at locations throughout the world. To adequately exploit the genetic material of female animals without requiring the female to give birth to all her offspring, a common practice is to inseminate the female by natural or artificial means and then extract the animal embryos at an age of three to five days. The extracted embryos are then typically frozen for shipment, processing, preservation or implantation at a later time.
It is well known in the art of animal husbandry to retrieve and collect mammalian embryos or ova from donor animals by flushing the animal's uterus with a solution and collecting the embryo bearing fluids, then passing the fiuids through a filtration device in which the embryos are collected. Typical prior art devices require the collected embryos and solution to be transferred in the laboratory to a petri dish for examination beneath a microscope and removal and packaging of the embryos. Transfer of fluid from the collecting container to the petri dish is undesirable as embryos may be lost or damaged in the transfer. Some embryo collectors employ collection vessels which are transparent and which have a flat base to permit positioning on a microscope table, however these known devices are cumbersome and have filter openings formed in the vessel sidewall or base which are of limited extent and which may allow embryos to be trapped without liquid suspension. Furthermore, conventional adhesive attachment of filters across outlet openings leaves undesirable crevices in which embryos may become trapped. Frequently the collection of the animal embryos is performed on site in a barn. This subjects the embryos to the ambient temperature which may be lower than the temperature of the donor animal.
To maintain maximum embryo viability and health, it is desirable to keep the embryos at the approximate body temperature of the donor during the collection and transportation procedure since the collection alone may take one-half to one hour and may be performed in a barn in cold weather.
What is needed is a compact and easy to use embryo transfer and collection device which may be placed directly under a microscope for extraction of embryos, which efficiently separates the embryos from the carrier fluid without subjecting them to damage, and which is protected from contamination.